Mobile communication terminals such as mobile phones can perform audio communication and data communication due to being provided with a module called a SIM (Subscriber Identity Module). An IMSI (International Mobile Subscriber Identity), which is a unique identification number assigned to the user of the mobile communication terminal by a carrier, is stored in this SIM. The IMSI includes an MCC (Mobile Country Code) that indicates the user's country, an MNC (Mobile Network Code) that indicates the carrier to which the user is subscribed, and an MSIN (Mobile Station Identification Number), which is a code for identifying the user. Since the IMSI includes information corresponding to the country and the carrier, one carrier can be used by each IMSI, and one country corresponds to each IMSI.
In recent years, the ETSI (European Telecommunications Standards Institute) has been examining a SIM standard that allows the IMSI to be changed via the mobile communication network. This type of SIM is called an eSIM (Embedded Subscriber Identity Module). With an eSIM, by changing the IMSI, a mobile communication terminal can directly use multiple carriers without relying on roaming.
With this type of mobile communication terminal that can receive communication services provided by multiple carriers, costs incurred due to roaming can be reduced by changing the IMSI according to the current location. For example, JP 2013-505658A discloses a management method in which subscriber network identification information is automatically provided to a subscribed communication device by a central network server. According to this management method, the central network server receives a notification regarding a change in the current location of the subscribed device, determines whether new subscriber network identification information is to be provided based on the notification, and, if it is determined that new information is to be provided, transmits subscriber network identification information selected based on the current location to the subscribed device. As a result, the mobile device operates using an appropriate IMSI and connects to a preferred network, thus making it possible for the mobile device user to avoid or reduce roaming charges.
Although the IMSI of an eSIM can be changed, multiple IMSIs cannot be used at the same time, and generally no distinction is made between an IMSI written to a SIM and an IMSI written to an eSIM. In other words, there are cases where an apparatus such as the server providing a communication service does not distinguish between a mobile communication terminal that can use an eSIM and a mobile communication terminal that cannot use an eSIM. Since the IMSI cannot be changed in a mobile communication terminal that cannot use an eSIM, it is useless to request the mobile communication terminal to change its IMSI. However, with the technique disclosed in Patent Document 1, when a customer enters a new country, an IMSI broker checks a subscribed user record and, if the SIM already has an appropriate IMSI in that country, attempts to update the subscriber's SIM by radio transmitting an appropriate IMSI update. In other words, the technique disclosed in JP 2013-505658A is based on the presumption that mobile communication terminals can use an eSIM, and does not envision the coexistence of this type of mobile communication terminal and mobile communication terminals that cannot use an eSIM.
Also, there are cases where a mobile communication terminal user desires to change the connected mobile communication network depending on the application program (hereinafter, referred to as “app”) executed in the mobile communication terminal. However, it has not been possible to realize this with the techniques described in prior JP 2013-505658A and the like.